In U.S. Pat. No. 3,984,350 a method of forming a high activity, low solubles producing, brown catalyst component comprising beta titanium trichloride is taught which has its prime utility in the polymerization of propylene and propylene dominated alpha-olefin mixtures when promoted with an alkylaluminum compound. Such component is a high surface area, large porosity material containing a small amount of one or more complexing agents. Although the component produces a large polymerization yield of crystalline polymer and a small solubles production compared to all prior art beta titanium trichloride catalyst components, further improvements can be of extreme commercial importance because of the size of yearly world production of such polymers. For example, even a few percent increase in crystalline polymer yield while maintaining the solubles level can produce savings in the millions of dollars per year range.
Now it has been found that if an additional material is added in the reduction, which is the first stage of producing the above-mentioned catalyst component, and, if such material is subsequently extracted by the organic electron pair donor material, the electron pair acceptor material, etc. prior to use as a catalyst component, a component of substantially increased crystalline polymer yield results which produces the same or slightly lower solubles.